Astronomers are trapped in the exquisitely painful limbo of knowing exactly where to look for Martian life, but being unable to do so for fear of sabotaging the mission.
After NASA’s announcement last week that they found definitive evidence of liquid water on Mars, the science community and the public at large were likely salivating at the mouth over the prospect of digging around in these water-containing streaks. This discovery has brought us closer than ever before to finding extraterrestrial life, and the most immediate question on people’s minds was probably, “So what are we doing about it?” Unfortunately, the answer is nothing. Not yet, anyway.
SEE ALSO: It's Official: Mars Has Liquid Water
Although NASA’s Curiosity rover has been exploring Mars for three years now, it can never traverse the 50 km separating it from the dark streaks containing water. The problem is contamination. Earthly microbes are surprisingly tenacious, and not even the vigorous pre-launch scrub-down given to all spacecraft, nor the 225 million km journey through the vacuum of space, is enough to completely obliterate them. The sides of the rover could be teeming with terrestrial bacteria that would love the opportunity to set up shop in Martian water seeps. If Curiosity were even to approach these sites, we would risk contaminating them with earthly bacteria and thus ruin any chance of knowing for sure whether Mars has ever developed life of its own.
According to a Reddit AMA conducted by a team of NASA scientists, the Curiosity rover would need to undergo a severe round of sterilization involving “autoclaving,” or super-high heat, that its electronic systems could not withstand. Of course, Curiosity doesn’t even have the proper equipment to look for signs of life, so it’s just as well that it stays away for now.
In fact, NASA is contractually obligated to keep the damp streaks as pristine as possible. The 1967 Outer Space Treaty forbids every country on Earth from “sending a mission, robot or human, close to a water source in the fear of contaminating it with life from Earth.” More specifically, the Planetary Protection policies maintained by the Committee on Space Research stipulate different levels of sterilization procedures for each spacecraft, depending on the destination and the likelihood of discovering life in those destinations.
Even worse, a review by the National Academy of Sciences and the European Science Foundation cautions that we may never be able to approach these habitable hotspots, called “special regions.” If sterilized rovers can still host microbial trespassers, human beings are cesspools of earthly life in comparison. In addition to microbial contamination, the heat released by crater formation or spacecraft operations could also compromise these regions by making them more friendly to life than otherwise.
So, what can we do? Are we doomed to delicately skirt around these fascinating regions forever, never to know for certain whether there’s even any reason for such prudence? Last year, NASA announced plans to send robots to Mars capable of 3D printing fresh equipment and rovers which would be less likely to be contaminated. Still, any future manned missions to Mars would have to completely avoid the most promising habitable areas. For now, it looks like we’ll have to wait for the world’s multiple space agencies to come up with a solution to this delicate dilemma.